The present invention relates to a switchgear for use in, for example, a substation and, more particularly, to a three-phase common enclosure or a three-phase package type gas-insulated switchgear which has isolators and earthing switches of three phases accommodated within a common enclosure.
A typical gas-insulated switchgear has a relatively small volume while providing sufficient electric insulation. More specifically, in a typical gas-insulated switchgear, isolators for disconnecting electrical connections to circuits, earthing switches for grounding the circuits, and so on are housed within a hermetically sealed enclosure having an insulation gas such as sulfur hexafluoride (SF.sub.6) gas or the like having excellent electrical insulation property filled therein. A gas-insulated switchgear of such construction is widely used at high-voltage class substations situated in urban areas so as to enable a reduction in a size of the installation sites.
In, for example, Japanese utility model unexamined publication no. 56-116810, two rod-like movable contact elements of an isolator and an earthing switch are disposed substantially in parallel with each other and, for reducing a length of an enclosure of the switchgear, Japanese patent unexamined publication no. 60-62807 proposes disposing driving portions of isolators and earthing switches within a radially extending cylindrical space formed in the enclosure.
In, for example, Japanese patent unexamined publication no. 61-170212, isolators and earthing switches of three phases are mounted on a bracket and fixed, as an integrated body, within an enclosure, with the isolators and earthing switches being disposed and extending in a direction transversely of a longitudinal direction of the enclosure.